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 A039995 Number of distinct primes which occur as subsequences of the sequence of digits of n. 6
 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1, 2, 0, 1, 0, 2, 0, 1, 1, 1, 1, 3, 1, 2, 1, 2, 1, 2, 1, 2, 2, 1, 1, 2, 1, 3, 1, 1, 0, 1, 1, 2, 0, 1, 0, 2, 0, 0, 1, 1, 2, 3, 1, 1, 1, 2, 1, 2, 0, 1, 1, 1, 0, 1, 0, 2, 0, 0, 1, 2, 2, 3, 1, 2, 1, 1, 1, 2, 0, 0, 1, 2, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 2, 0, 0, 0, 2, 1, 3, 0, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,13 COMMENTS a(n) counts subsequences of digits of n which denote primes. a(A094535(n)) = n and a(m) < n for m < A094535(n); A039995(39467139)=100, cf. A205956. [Reinhard Zumkeller, Feb 01 2012] LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 EXAMPLE a(103)=3; the 3 primes are 3, 13 and 103. MATHEMATICA cnt[n_] := Module[{d = IntegerDigits[n]}, Length[Union[Select[FromDigits /@ Subsets[d], PrimeQ]]]]; Table[cnt[n], {n, 105}] (* T. D. Noe, Jan 31 2012 *) PROG (Haskell) import Data.List (subsequences, nub) a039995 n = sum \$    map a010051 \$ nub \$ map read (tail \$ subsequences \$ show n) -- Reinhard Zumkeller, Jan 31 2012 CROSSREFS A039997 counts only the primes which occur as substrings, i.e. contiguous subsequences. Cf. A035232. Cf. A010051. Sequence in context: A113686 A193403 A039997 * A035232 A091603 A325036 Adjacent sequences:  A039992 A039993 A039994 * A039996 A039997 A039998 KEYWORD nonn,base AUTHOR STATUS approved

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Last modified September 25 10:38 EDT 2020. Contains 337337 sequences. (Running on oeis4.)